From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932233AbbCEIjN (ORCPT ); Thu, 5 Mar 2015 03:39:13 -0500 Received: from mx1.redhat.com ([209.132.183.28]:53560 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751503AbbCEIjM (ORCPT ); Thu, 5 Mar 2015 03:39:12 -0500 Date: Thu, 5 Mar 2015 09:39:05 +0100 From: "Michael S. Tsirkin" To: Rusty Russell Cc: linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org Subject: Re: [PATCH] virtio_balloon: set DRIVER_OK before using device Message-ID: <20150305083905.GA11474@redhat.com> References: <1425474779-29412-1-git-send-email-mst@redhat.com> <877fuwjgqw.fsf@rustcorp.com.au> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <877fuwjgqw.fsf@rustcorp.com.au> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Mar 05, 2015 at 01:24:47PM +1030, Rusty Russell wrote: > "Michael S. Tsirkin" writes: > > virtio spec requires that all drivers set DRIVER_OK > > before using devices. While balloon isn't yet > > included in the virtio 1 spec, previous spec versions > > also required this. > > > > virtio balloon might violate this rule: probe calls > > kthread_run before setting DRIVER_OK, which might run > > immediately and cause balloon to inflate/deflate. > > > > To fix, call virtio_device_ready before running the kthread. > > > > Signed-off-by: Michael S. Tsirkin > > Replied, CC'd stable. Did you mean applied? > Thanks, > Rusty. > > > > --- > > drivers/virtio/virtio_balloon.c | 2 ++ > > 1 file changed, 2 insertions(+) > > > > diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c > > index 5a6ad6d..6a356e3 100644 > > --- a/drivers/virtio/virtio_balloon.c > > +++ b/drivers/virtio/virtio_balloon.c > > @@ -508,6 +508,8 @@ static int virtballoon_probe(struct virtio_device *vdev) > > if (err < 0) > > goto out_oom_notify; > > > > + virtio_device_ready(vdev); > > + > > vb->thread = kthread_run(balloon, vb, "vballoon"); > > if (IS_ERR(vb->thread)) { > > err = PTR_ERR(vb->thread); > > -- > > MST